One of the tasks in servicing military aircraft is to replace items such as bombs, rockets and fuel tanks which have been ejected in a previous mission. Bombs and rockets are usually carried externally and are releasably held by appropriate pylons under the aircraft wings. While small ordnance items could be assembled manually, the attachment of heavy items, for example bombs weighing hundreds of kilograms, requires the use of a mechanical loader. For this purpose vehicles have been developed which have a low long front to allow access under an aircraft wing, and a hydraulic boom between the front wheels to which the required item is attached and then raised in a position allowing attachment to the aircraft pylon. The loader vehicle may then be used to collect, transport and raise further items. Such vehicle will henceforth be referred to as a bomb loader, or simply as the vehicle.
Hydraulically operated bomb loaders are in service in many countries, but the functioning thereof leaves much to be desired. A bomb loader must meet somewhat contradicting requirements. Fast execution of its task is essential when the aircraft to be loaded is to carry out several successive missions in a tight time frame. However, due to the nature of the loads being handled, it is mandatory that highest possible safety standards are adhered to. Furthermore, the bomb loader is often required to maneuver in restricted space areas such as aircraft hangars wherein aircraft and servicing equipment leave little free space. Meeting these requirements is the primary aim of the present invention.
A patent search carried out failed to produce any relevant prior art. However it is known that the British firm “Portsmouth Aviation Ltd.” manufactures a motorized bomb loader as well as a Trolley Weapon Loading device referred to as Type R Mk2. Hydraulic power is provided by a hand pump, and the trolley naturally requires a tractor for locomotion.
A further prior-art bomb loader is known as the MJ-1, which is however not equipped with safety features which are an important part of the present invention. This vehicle also has a turning circle twice as large as the subject of the present invention.
It is therefore one of the objects of the present invention to obviate the disadvantages of prior art bomb loading vehicles and to provide a bomb loader which is more maneuverable than previously known vehicles. It is a further object of the present invention to provide multiple safety features aimed at carrying out the allotted task without mishap.
The present invention achieves the above objects by providing a motorized hydraulically-operated and driven aircraft loading vehicle particularly suited for the loading of bombs, the vehicle being provided with a pair of hydraulically-operated arms for raising and lowering a load, the vehicle having two selectable operation modes, a first, working mode providing four-wheel hydraulic steering and enabling the vehicle to be driven at a small turning radius, and at a speed of up to 10 km/h, and a second, traveling mode wherein the rear wheel steering system is automatically locked at straight orientation and the vehicle can be road driven at a speed of up to 20 km/h. All systems of the vehicle are computer controlled.
In a preferred embodiment of the present invention there is provided an aircraft loading vehicle wherein two independent braking systems are provided, a first braking system of conventional design for normal use and a second braking system hydraulically operated and automatically applied in case of loss of hydraulic pressure.
In a further preferred embodiment of the present invention the systems are electrically controlled and not mechanically.
In a most preferred embodiment of the present invention there is provided an aircraft loading vehicle further including an emergency hand-operated pump, the pump being usable to release the second braking system and to operate the arms upwards or downwards.
Yet further embodiments of the invention will be described hereinafter.
It will thus be realized that the novel device of the present invention makes significant progress over the prior art in providing a bomb loader that is faster, safer and easier to maneuver than previously known vehicles for this purpose. A further advantage of the present bomb loader is that the diesel engine driving the hydraulic system when idle runs at only 900 rpm, thus reducing noise, fuel consumption and engine wear. Computer 95 converts the engine speed signal into an automotive drive characteristics to control the non feed back proportional axial piston pump, plus an electric two speed bent axis motor.
The computer 95 controls the axial piston pump via two proportional pressure reducing valves. The automotive control curve, is a function of the engine speed measured with the integral pulse pickup mounted on the pump.
Two driving modes conditions.
Selected Via Mode Switch:
                A. Working mode/Combined front and rear steering.        B. Traveling mode/Front steering only.        
It will further be understood that the vehicle is not limited to the previously-specified duties but can be used for lifting and transferring loads for many other purposes, and easily be adapted for lifting a person, for example a maintenance technician.
The invention will now be described further with reference to the accompanying drawings, which represent by example preferred embodiments of the invention. Structural details are shown only as far as necessary for a fundamental understanding thereof. The electrical and hydraulic circuits show only essential features and do not include items of conventional vehicle design. The described examples, together with the drawings, will make apparent to those skilled in the art how further forms of the invention may be realized.